1. Field of Invention
The present invention relates to novel hydroxyalkyl ether derivatives of rutin poly(H-)sulfates and salts thereof and their use as inhibitors of the complement system of warm-blooded animals.
2. Description of the Prior Art
Certain sulfated polysaccharides have been reported as having complement inhibiting activity, for example, heparin, J. Infect. Dis. 44: 250-253 (1929); carrageenin, Immunology 8: 291 (1965); and pentosan polysulfoester, Chemical Abstracts 75: 33179s (1971). The basic rutin poly(H-)sulfates and salts thereof are the subject of application Ser. No. 181,251, filed Aug. 25, 1980, now Pat. No. 4,334,058 and its parent applications Ser. No. 62,587, filed July 31, 1979, now abandoned, and Ser. No. 966,423, filed Dec. 4, 1978, now abandoned, all incorporated herein by reference. However, no art is known which discloses anticomplementary activity for the novel hydroxyalkyl derivatives of rutin poly(H-)sulfate which are the subject of this invention.
A rutin sulfate sodium salt ("rutin water soluble") is commercially available from E. Merck, Darmstadt, West Germany, Catalogue No. 500014. This material, which is useful as an injectable form of Vitamin P, has an analysis, S=5.45%. "Rutin water soluble" has been tested for complement inhibiting activity, using the tests disclosed herein, and has been found lacking in complement inhibiting activity. Sulfation of "rutin water soluble" produces the rutin poly(H-)-sulfates of the aforementioned U.S. patent applications, (sulfur analysis S=16.5%) which are active as complement inhibitors.
The term "complement" refers to a complex group of proteins in body fluids that, working together with antibodies or other factors, play an important role as mediators of immune, allergic, immunochemical and/or immunopathological reactions. The reactions in which complement participates take place in blood serum or in other body fluids, and hence are considered to be humoral reactions.
With regard to human blood, there are at present more than 20 proteins in the complement system consisting of the so-called classical and alternative pathways. These complement proteins are generally designated by the letter C and by number: C1, C2, C3 and so on up to C9. The complement protein C1 is actually an assembly of subunits designated C1q, C1r and C1s. The numbers assigned to the complement proteins reflect the sequence in which they become active, with the exception of complement protein C4, which reacts after C1 and before C2. The numerical assignments for the proteins in the complement system were made before the reaction sequence was fully understood. A more detailed discussion of the complement system and its biochemical, biological and pathological role in the body processes can be found in, for example, Bull. World Health Org. 39: 935 (1968); Ann. Rev. Medicine 19: 1 (1968); The John Hopkins Med. J. 128: 57 (1971); Harvey Lectures 66: 75 (1972); The New England Journal of Medicine 287: 452, 489, 545, 592, 642 (1972); Scientific American 229(5): 54 (1973); Federation Proceedings 32: 134 (1973); Medical World News, October 11, 1974, p. 53; J. Allergy Clin. Immunol. 53: 298 (1974); Cold Spring Harbor Conf. Cell Proliferation 2/Proteases Biol. Control: 229 (1975); Ann. Review of Biochemistry 44: 697 (1975); Complement in Clinical Medicine, Disease-a-Month (1975); Complement, Scope, December 1975; Annals of Internal Medicine 84: 580 (1976); Transplant Reviews: 32 (1976); "Complement: Mechanisms and Functions", Prentice-Hall, Englewood Cliffs, N.J. (1976); Essays Med. Biochem. 2: 1 (1976); Hospital Practice 12: 33 (1977); Perturbation of Complement in Disease, Chap. 15 in Biological Amplification Systems in Immunology (Ed. Day and Good), Plenum, New York and London (1977); Am. J. Clin. Pathology 68: 647 (1977); Biochemical Soc. Transactions 5: 1659 (1977); The Harvey Lecture Series 72: 139 (1976-1977); J. Periodontology 48: 505 (1977); Biochemical Soc. Transactions 6: 798 (1978); Clin. and Experimental Dermatology 4: 271 (1979); Reviews of Infectious Diseases 1: 483 (1979).
The complement system (e.g. classical pathway) can be considered to consist of three sub-systems: (1) a recognition unit (C1q) which enables it to combine with antibody molecules that have detected a foreign invader; (2) an activation unit (C1r, C1s, C2, C4, C3) which prepares a site on the neighboring membrane; and (3) an attack unit (C5, C6, C7, C8 and C9) which creates a "hole" in the membrane. The membrane attack unit is non-specific; it destroys invaders only because it is generated in their neighborhood. In order to minimize damage to the host's own cells, its activity must be limited in time. This limitation is accomplished partly by the spontaneous decay of activated complement and partly by interference by inhibitors and destructive enzymes. The control of complement, however, is not perfect, and there are times when damage is done to host's cells. Immunity is, therefore, a double-edged sword.
Activation of the complement system also accelerates blood clotting. This action comes about by way of the complement-mediated release of a clotting factor from platelets. The biologically active complement fragments and complexes can become involved in reactions that damage the host's cells, and these pathogenic reactions can result in the development of immune-complex diseases. For example, in some forms of nephritis, complement damages the basal membrane of the kidney, resulting in the escape of protein from the blood into the urine. The disease disseminated lupus erythematosus belongs in this category; its symptoms include nephritis, visceral lesions and skin eruptions. The treatment of diphtheria or tetanus with the injection of large amounts of antitoxin sometimes results in serum sickness, an immune-complex disease. Rheumatoid arthritis also involves immune complexes. Like disseminated lupus erythematosus, it is an autoimmune disease in which the disease symptoms are caused by pathological effects of the immune system in the host's tissues. In summary, the complement system has been shown to be involved with inflammation, coagulation, fibrinolysis, antibody-antigen reactions and other metabolic processes.
In the presence of antibody-antigen complexes the complement proteins are involved in a series of reactions which may lead to irreversible membrane damage if they occur in the vicinity of biological membranes. Thus, while complement constitutes a part of the body's defense mechanism against infection it also results in inflammation and tissue damage in the immunopathological process. The nature of certain of the complement proteins, suggestions regarding the mode of complement binding to biological membranes and the manner in which complement effects membrane damage are discussed in Annual Review in Biochemistry 38: 389 (1969); J. Experimental Medicine 141: 724 (1975); J. of Immunology 116: 1431 (1976); 119: 1, 1195, 1358, 1482 (1977); 120: 1841 (1978); Immunochemistry 15: 813 (1978); J. Biological Chemistry 254: 9908 (1979).
A variety of substances have been disclosed as inhibiting the complement system i.e., as complement inhibitors. For example, the compounds, 3,3'-ureylenebis[6-(2-amino-8-hydroxy-6-sulfo-1-naphthylazo)benzenesulfoni c acid], tetrasodium salt (chlorazol fast pink), heparin and a sulphated dextran have been reported to have an anticomplementary effect, British Journal of Experimental Pathology 33: 327 (1952). German Pat. No. 2,254,893 or South African Pat. No. 727,923 discloses certain 1-(diphenylmethyl)-4-(3-phenylallyl)piperazines useful as complement inhibitors. Other chemical compounds having complement inhibiting activity are disclosed in, for example, Journal of Medicinal Chemistry 12: 415, 902, 1049, 1053 (1969); Canadian Journal of Biochemistry 47: 547 (1969); The Journal of Immunology 104: 279 (1970); The Journal of Immunology 106: 241 (1971); The Journal of Immunology 111: 1061 (1973); Biochim. Biophys. Acta 317: 539 (1973); Life Sciences 13: 351 (1973); Journal of Immunology 113: 584 (1974); Immunology 26: 819 (1974); Journal of Medicinal Chemistry 17: 1160 (1974); Biochim. Biophys. Res. Comm 67: 225 (1975); Ann. N.Y. Acad. Sci. 256: 441 (1975); Journal of Medicinal Chemistry 19: 634, 1079 (1976); Journal of Immunology 118: 466 (1977); Arch. Int. Pharmacodyn. 226: 281 (1977); Biochem. Pharmacol. 26: 325 (1977); Journal Pharm. Sci. 66: 1367 (1977); Chem. Pharm. Bull. 25: 1202 (1977); Biochim. Biophys. Acta 484: 417 (1977); Journal Clin. Microbiology 5: 278 (1977); Immunochemistry 15: 231 (1978); Immunology 34: 509 (1978); J. Experimental Medicine 147: 409 (1978); Thrombosis Research 14: 179 (1979); J. Immunology 122: 2418 (1979); J. Chem. Soc. Chem. Comm. 726 (1979); Immunology 36: 131 (1979); Biochim. Biophys. Acta 611: 196 (1980); and J. Med Chem. 23:240 (1980).
It has been reported that the known complement inhibitors, epsilon-aminocaproic acid and tranexamic acid, have been used with success in the treatment of hereditary angioneurotic edema, a disease state resulting from an inherited deficiency of lack of function of the serum inhibitor of the activated first component of complement (C1 inhibitor), The New England Journal of Medicine 286: 808 (1972); 287: 452 (1972); Ann. Intern. Med 84: 580 (1976); J. Allergy and Clin. Immunology 60: 38 (1977). Also androgenic steroids have been used successfully in the treatment of this phisiological disorder; see Medicine 58: 321 (1979); Arthritis and Rheumatism 22: 1295 (1979); American J. Medicine 66: 681 (1979); and J. Allergy Clinical Immunology 65: 75 (1980).
It has also been reported that the drug pentosanpolysulfoester has an anticomplementary activity on human serum, both in vitro and in vivo, as judged by the reduction in total hemolytic complement activity; Pathologie Biologie 25: 33; 25 (2): 105; 25 (3): 179 (1977).